TW202415205A - Electronic device and method of manufacturing the same - Google Patents

Abstract

An electronic device includes a power module, a heat sink and a multilayered metal layer. The power module includes a power unit and a metal surface. The power unit is thermally connected to a metal surface. The heat sink includes an aluminum body. The multilayered metal layer is located between the aluminum body and the metal hosing, and is fixed to the metal surface through a bonding layer.

Description

Electronic device and method of manufacturing the same

The present invention relates to an electronic device, in particular to an electronic device with a heat sink and a manufacturing method of the electronic device.

Since aluminum and aluminum alloys have a high affinity for oxygen, the surface oxides they produce will affect the bonding strength between the coating and the aluminum. Therefore, the traditional method is to use a galvanizing process to replace the surface, then immerse the aluminum or aluminum alloy in the plating solution, and then electroplate other metal layers on the surface for welding.

However, since aluminum easily reacts with acid and alkali, causing corrosion of parts, and when the aluminum has a poor zinc replacement layer, the surface electroplating has poor bonding with other metals, thus affecting the direct welding of parts to aluminum products. Therefore, a treatment method different from conventional electroplating must be adopted to obtain a coating with good bonding on aluminum products.

It can be seen that the above technology still has inconveniences and defects, and needs to be further improved. Therefore, how to effectively solve the above inconveniences and defects is one of the important research and development topics at present, and has also become a goal that needs to be improved urgently in the current related fields.

One purpose of the present invention is to provide an electronic device and a manufacturing method thereof to solve the difficulties mentioned in the above prior art.

An embodiment of the present invention provides an electronic device. The electronic device includes a connection layer, a power module, a heat sink and a composite metal layer. The power module includes at least one power unit and a metal surface, and the power unit is thermally connected to the metal surface. The heat sink includes an aluminum body. The composite metal layer is formed between the aluminum body and the metal surface, and is fixed to the metal surface through the connection layer.

According to one or more embodiments of the present invention, in the above-mentioned electronic device, the composite metal layer includes an interface stabilizing layer and a metal bonding film. The interface stabilizing layer is directly formed on one side of the aluminum body. The metal bonding film is directly formed on one side of the interface stabilizing layer opposite to the aluminum body and is located between the interface stabilizing layer and the metal surface.

According to one or more embodiments of the present invention, in the above-mentioned electronic device, the interface stabilizing layer is one of a titanium layer and a platinum layer.

According to one or more embodiments of the present invention, in the above-mentioned electronic device, the metal bonding film is a copper layer.

According to one or more embodiments of the present invention, in the above-mentioned electronic device, the composite metal layer further includes an electroplated metal layer. The electroplated metal layer is directly formed on one side of the metal bonding film opposite to the interface stabilizing layer and is located between the metal bonding film and the metal surface. The connecting layer is a solder layer, and the electroplated metal layer is soldered to the surface through the solder layer.

According to one or more embodiments of the present invention, in the above-mentioned electronic device, the electroplated metal layer is one of a copper-plated layer and a nickel-plated layer.

According to one or more embodiments of the present invention, in the above-mentioned electronic device, the connection layer is a sintered deposition layer, and the sintered deposition layer is directly between the metal bonding film and the metal surface.

According to one or more embodiments of the present invention, in the above-mentioned electronic device, the power module further includes a metal base plate, the metal base plate carries and contacts the power unit, and the metal surface is the surface of the metal base plate.

According to one or more embodiments of the present invention, in the above-mentioned electronic device, the metal surface is a metal coating located on the surface of the power module.

An embodiment of the present invention provides a method for manufacturing an electronic device. The manufacturing method includes a plurality of steps as follows: providing an aluminum body of a heat sink; providing a metal surface of a power module; forming a composite metal layer on the aluminum body; and fixing the composite metal layer to the metal surface through a connecting layer.

According to one or more embodiments of the present invention, in the above-mentioned manufacturing method, the step of forming a composite metal layer on an aluminum body further includes a plurality of detailed steps as follows: partially shielding the surface of the aluminum body and exposing a sputtering area from the surface; moving the aluminum body into a vacuum chamber and performing a vacuum sputtering process on the sputtering area of the aluminum body so that an interface stabilizing layer is sputtered at a position of the surface of the aluminum body corresponding to the sputtering area, and the interface stabilizing layer is one of a titanium layer and a platinum layer; and performing another vacuum sputtering process on the aluminum body again so that a metal bonding film is directly formed on the interface stabilizing layer, and the metal bonding film is a copper layer.

According to one or more embodiments of the present invention, in the above-mentioned manufacturing method, the step of directly forming the metal bonding film on the interface stabilizing layer further includes a plurality of detailed steps as follows: the aluminum body is moved from the vacuum chamber into an electrolyte, and an electroplating process is performed on the aluminum body, so that an electroplated metal layer is directly formed on the metal bonding film, and the electroplated metal layer is one of a copper-plated layer and a nickel-plated layer.

According to one or more embodiments of the present invention, in the above-mentioned manufacturing method, the step of fixing the composite metal layer to the metal surface through the connecting layer further includes a plurality of detailed steps as follows: placing a solder between the electroplated metal layer and the metal surface to form an object to be processed; and sending the object to be processed into a reflow soldering furnace so that the solder after being hot-melted directly forms a solder layer capable of welding the electroplated metal layer and the metal surface.

According to one or more embodiments of the present invention, in the above-mentioned manufacturing method, the step of fixing the composite metal layer to the metal surface through the connecting layer further includes a plurality of detailed steps as follows: disposing a sintered powder between the metal bonding film and the metal surface to form a workpiece to be processed; and subjecting the workpiece to a sintering process so that the sintered powder after sintering forms a sintered coating layer capable of welding the metal bonding film and the metal surface.

According to one or more embodiments of the present invention, in the above-mentioned manufacturing method, the metal base plate of the power module carries and contacts the power unit of the power module, and the metal surface is the surface of the metal base plate.

According to one or more embodiments of the present invention, in the above-mentioned manufacturing method, the metal surface is a metal coating located on the surface of the power module.

Thus, through the structures described in the above embodiments, the present invention can complete the welding process of aluminum metal and aluminum alloy without using the galvanizing process, and can provide full or partial surface treatment for aluminum and aluminum alloy according to specific areas, thereby reducing the cost of metal usage in the post-process plating.

The above description is only used to explain the problem to be solved by the present invention, the technical means for solving the problem, and the effects produced, etc. The specific details of the present invention will be introduced in detail in the following implementation method and related drawings.

The following will disclose multiple embodiments of the present invention with drawings. For the purpose of clarity, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. In other words, in each embodiment of the present invention, these practical details are not necessary. In addition, for the purpose of simplifying the drawings, some commonly used structures and components will be depicted in the drawings in a simple schematic manner.

FIG. 1 is a schematic diagram of an electronic device 10 of an embodiment of the present invention. FIG. 2 is a partial cross-sectional view of FIG. 1 along line segment AA. FIG. 3 is a top view of the electronic device 10 of FIG. 1. As shown in FIG. 1 to FIG. 3, the electronic device 10 includes a power module 200, a heat sink 300, and a composite metal layer 400. The power module 200 includes a metal surface and a plurality of power units 220. The metal surface is, for example, the surface of a metal base plate 210. The metal base plate 210 carries and contacts these power units 220, so that these power units 220 are thermally connected to the metal base plate 210. The power unit 220 includes a chip and leads (not shown in the figure), however, the present invention is not limited thereto. The heat sink 300 includes an aluminum body 310. The composite metal layer 400 is formed between the aluminum body 310 and the metal base plate 210 , and the composite metal layer 400 is fixed to the metal base plate 210 via a connecting layer 500 . In this way, the heat energy of the power module 200 can be transferred to the aluminum body 310 of the heat sink 300 through the composite metal layer 400 .

More specifically, in this embodiment, the aluminum body 310 includes an inlet 312, an outlet 313, and an internal channel 314. The internal channel 314 is formed in the aluminum body 310 and is connected to the inlet 312 and the outlet 313. Therefore, the fluid can enter the internal channel 314 from the inlet 312, and after taking away the heat energy of the aluminum body 310, leave the internal channel 314 from the outlet 313. However, the present invention is not limited to this heat dissipation structure.

In addition, in this embodiment, the composite metal layer 400 includes an interface stabilizing layer 410, a metal bonding film 420, and an electroplated metal layer 430. The interface stabilizing layer 410 is directly formed on one side of the aluminum body 310. The metal bonding film 420 is directly formed on one side of the interface stabilizing layer 410 opposite to the aluminum body 310, and is located between the interface stabilizing layer 410 and the metal base plate 210. The electroplated metal layer 430 is directly formed on one side of the metal bonding film 420 opposite to the interface stabilizing layer 410, and is located between the metal bonding film 420 and the metal base plate 210. The connecting layer 500 is a solder layer 510 capable of soldering the electroplated metal layer 430 and the metal base plate 210. Therefore, the electroplated metal layer 430 is fixed to the surface of the metal base plate 210 through the solder layer 510, so that the metal base plate 210, the composite metal layer 400 and the aluminum body 310 are integrated into one body. The composite metal layer 400 is not limited to being partially or completely formed on a portion of the top surface 311 of the aluminum body 310, however, the present embodiment is not limited thereto.

For example, the metal base plate 210 is copper, aluminum or other similar materials, however, the present invention is not limited to the above materials. The interface stabilizing layer 410 is, for example, a titanium layer, a platinum layer or other similar materials, and the thickness of the interface stabilizing layer 410 is, for example, 0.15 micrometers (μm), or not more than 0.5 micrometers (μm), however, the present invention is not limited to the above materials and thicknesses. The metal bonding film 420 is a copper layer or other similar materials, and the thickness of the metal bonding film 420 is, for example, 0.3 micrometers (μm), or not more than 1 micrometer (μm), however, the present invention is not limited to the above materials and thicknesses. The electroplated metal layer 430 is, for example, a copper-plated layer, a nickel-plated layer, or other similar materials, and the thickness of the electroplated metal layer 430 is, for example, 3 micrometers (μm), or not more than 20 micrometers (μm), however, the present invention is not limited to the above materials and thicknesses. The solder layer 510 is, for example, tin-lead solder, lead-free solder, solder paste, or other similar materials.

As shown in FIG. 2 , the stacked structure 100 shown in FIG. 2 includes a copper layer, a composite metal layer 400 and an aluminum layer. The composite metal layer 400 is stacked between the copper layer and the aluminum layer, and the composite metal layer 400 is fixed to the copper layer through the connecting layer 500 .

FIG. 4 is a partial cross-sectional view of an electronic device according to an embodiment of the present invention, and its cross-sectional area is the same as the cross-sectional area of FIG. 4. As shown in FIG. 4, the layered structure 100 of this embodiment is substantially the same as the layered structure 101 of FIG. 2, and the difference is that the composite metal layer 401 of this embodiment does not have the electroplated metal layer 430, and is fixedly connected to the metal base plate 210 through another connecting layer (i.e., the sintered coating layer 520). In other words, the composite metal layer 401 only has the interface stabilizing layer 410 and the metal bonding film 420, and the metal bonding film 420 is fixedly connected to the metal base plate 210 through the sintered coating layer 520.

For example, the sintered coating layer 520 is a silver coating layer, a gold coating layer or other similar materials, and the thickness of the sintered coating layer 520 is, for example, 0.05 micrometers (μm), or not more than 1 micrometer (μm). However, the present invention is not limited to the above materials and thicknesses.

FIG. 5 is a flow chart of a method for manufacturing an electronic device 10 according to an embodiment of the present invention. As shown in FIG. 1 and FIG. 5, the method for manufacturing the electronic device 10 includes steps 501 to 504 as follows. In step 501, an aluminum body 310 of a heat sink 300 is provided. In step 502, a metal base plate 210 of a power module 200 is provided. In step 503, a composite metal layer 400 is formed on the aluminum body 310. In step 504, the composite metal layer 400 is fixed to the metal base plate 210 through a connecting layer 500.

FIG. 6 is a detailed flow chart of step 503 and step 504 of FIG. 5. As shown in FIG. 5 and FIG. 6, the above-mentioned step 503 to step 504 further includes several steps 601 to step 607 as follows.

In step 601, the surface (such as the top surface 311) of the aluminum body 310 is cleaned. In step 602, the surface (such as the top surface 311) of the aluminum body 310 is partially shielded, for example, by using a film or a mask, so as to expose a sputtered area (not shown) from the surface (such as the top surface 311). However, the method is not limited thereto, and other embodiments may not shield the surface (such as the top surface 311) of the aluminum body 310. In step 603, the aluminum body 310 is moved into a vacuum chamber of a vacuum sputtering process, and a vacuum sputtering process is performed on the exposed sputtering area of the surface (such as the top surface 311) of the aluminum body 310, so that a sputtering layer (such as the above-mentioned interface stabilizing layer 410) is sputtered at the position of the aluminum body 310 corresponding to the sputtering area. In step 604, another vacuum sputtering process is performed on the aluminum body 310 in the vacuum chamber again, so that another sputtering layer (such as the above-mentioned metal bonding film 420) is directly stacked on the sputtering layer (such as the above-mentioned interface stabilizing layer 410). In step 605, the aluminum body 310 is moved from the vacuum chamber into an electrolyte, and an electroplating process is performed on the aluminum body 310, so that an electroplated metal layer 430 is directly formed on another sputtered layer (such as the metal bonding film 420 mentioned above). In step 606, a solder is arranged between the electroplated metal layer 430 and the metal base plate 210 to form a workpiece to be processed. In step 607, the workpiece to be processed is sent into a reflow furnace, so that the hot-melted solder directly forms a solder layer 510 capable of welding the electroplated metal layer 430 and the metal base plate 210.

More specifically, in this embodiment, the environmental variables and operating variables of the above vacuum sputtering process (or coating process) are as follows. More specifically, the plasma power is set to 800W, the gas flow rate is 250±50sccm/vacuum value is 5.0E-2/time is 240sec, and the O2 oxygen flow rate is 60sccm and the AR argon flow rate is 150sccm, and the target power is 4kw. Then, after the product is placed, the power supply unit (PSU) is turned on to start the vacuum pump to evacuate, and the gas is turned on and injected to start the vacuum coating process (or coating process).

The environmental variables and operation variables of the above electroplating process are as follows. More specifically, after pre-treatment cleaning and degreasing, the surface is first activated by acid; then, the electroplating controls the concentration and required thickness of each metal electroplating solution to adjust the current and time; then, multiple tanks of water are used to wash away the solution; then, the main residual water is blown away by a wind knife for, for example, 5 seconds; then, the aluminum body 310 is finally dried according to parameters such as 120°C/120 seconds.

FIG. 7 is a detailed flow chart of another embodiment of step 504 of FIG. 5. As shown in FIG. 7, the detailed flow of this embodiment is substantially the same as the detailed flow of FIG. 6, except that after step 601 to step 604, the detailed flow of this embodiment does not proceed to step 605 to step 607, but instead proceeds to step 701 and step 702 as follows.

In step 701, a sintered powder is disposed between the metal bonding film 420 and the metal base plate 210 to form a workpiece. In step 702, the workpiece is subjected to a sintering process so that the sintered powder forms a sintered coating layer 520 capable of welding the metal bonding film 420 and the metal base plate 210. In this way, the heat energy of the power module 200 can be transferred to the aluminum body 310 of the heat sink 300 through the sintered coating layer 520. For example, the sintered powder is usually a paste or slurry type, however, the present invention is not limited thereto.

More specifically, in this embodiment, the environmental variables and operation variables of the sintering process are as follows. More specifically, after the object to be processed is coated with silver paste, it is stacked with the power module 200 and placed in a heating chamber. For example, the temperature is raised to 150°C within 50 minutes, maintained for 50 minutes, heated to 200°C within 15 minutes, maintained for 80 minutes, and cooled to room temperature within 50 minutes. Depending on the use of different silver sintering materials, there are variables such as vacuum or special atmosphere or air, pressure of 10MPa or no pressure, and different heating temperature curves.

FIG8 is a schematic diagram of an electronic device 11 according to an embodiment of the present invention. Referring to FIG8, the electronic device 11 of this embodiment is substantially the same as the electronic device 10 of FIG1, except that the metal surface is, for example, a metal coating 211 located on the surface of the power module 202.

More specifically, the power module 202 includes a housing 221, a chip 222, leads 223, 224, an insulating substrate 225 and a packaging portion 230. The aluminum body 310 covers the bottom surface of the housing 221 to define a receiving groove 226 on the front surface of the housing 221. The insulating substrate 225 (such as a copper-clad insulating substrate, Direct Bonded Copper, DBC) is located in the receiving groove 226, and its exterior is coated with the above-mentioned metal coating 211 (such as a thick copper foil directly coated on a ceramic substrate). The chip 222 is fixed on the insulating substrate 225, one of the leads 223 is connected to the chip 222 and one of the terminals 227 in the housing 221, and the other lead 224 is connected to the circuit (not shown) on the insulating substrate 225 and the other terminal 228 in the housing 221. The composite metal layer 400 is connected between the metal coating 211 and the aluminum body 310 through the solder layer 510. The package 230 is filled in the receiving groove 226 and covers the chip 222, the leads 223, 224, the insulating substrate 225 and the composite metal layer 400.

Thus, through the structures described in the above embodiments, the present invention can complete the welding process of aluminum metal and aluminum alloy without using the galvanizing process, and can provide full or partial surface treatment for aluminum and aluminum alloy according to specific areas, thereby reducing the cost of metal usage in the post-process plating.

Finally, the above disclosed embodiments are not intended to limit the present invention. Anyone skilled in the art can make various changes and modifications within the spirit and scope of the present invention, and all of them can be protected by the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the attached patent application.

10, 11: Electronic device 100, 101: Stacked structure 200, 202: Power module 210: Metal base 211: Metal coating 220: Power unit 221: Housing 222: Chip 223, 224: Leads 225: Insulating substrate 226: Accommodation groove 227, 228: Terminals 230: Package 300: Heat sink 310: Aluminum body 311: Top surface 312: Inlet 313: Outlet 314: Internal channel 400, 401: Composite metal layer 410: Interface stabilizing layer 420: Metal bonding film 430: Electroplated metal layer 500: Bonding layer 501~504: Step 510: Solder layer 520: Sintered plating layer 601~607: Step 701~702: Step AA: Line segment

In order to make the above and other purposes, features, advantages and embodiments of the present invention more clearly understandable, the attached drawings are described as follows: FIG. 1 is a schematic diagram of an electronic device of an embodiment of the present invention; FIG. 2 is a partial cross-sectional view made along line segment AA of FIG. 1; FIG. 3 is a top view of the electronic device of FIG. 1; FIG. 4 is a partial cross-sectional view of an electronic device of an embodiment of the present invention, and its cross-section is the same as that of FIG. 2; FIG. 5 is a flow chart of a method for manufacturing an electronic device of an embodiment of the present invention; FIG. 6 is a detailed flow chart of steps 503 and 504 of FIG. 5; FIG. 7 is a detailed flow chart of another embodiment of step 504 of FIG. 5; and FIG. 8 is a schematic diagram of an electronic device of an embodiment of the present invention.

Domestic storage information (please note in the order of storage institution, date, and number) None Foreign storage information (please note in the order of storage country, institution, date, and number) None

10: Electronic devices

200: Power module

210:Metal base plate

220: Power unit

300: Radiator

310: Aluminum body

311: Top

312:Entrance

313:Exit

314: Internal passage

400: Composite metal layer

410: Interface stabilization layer

420:Metal bonding film

430: Electroplating metal layer

500: Link layer

510: Solder layer

AA: Line segment

Claims (16)

An electronic device comprises: a connecting layer; a power module comprising at least one power unit and a metal surface, wherein the power unit is thermally connected to the metal surface; a heat sink comprising an aluminum body; and a composite metal layer located between the aluminum body and the metal surface and fixed to the metal surface through the connecting layer. An electronic device as described in claim 1, wherein the composite metal layer comprises: an interface stabilizing layer formed directly on one side of the aluminum body; and a metal bonding film formed directly on one side of the interface stabilizing layer opposite to the aluminum body and located between the interface stabilizing layer and the metal surface. An electronic device as described in claim 2, wherein the interface stabilizing layer is one of a titanium layer and a platinum layer. An electronic device as described in claim 2, wherein the metal bonding film is a copper layer. An electronic device as described in claim 2, wherein the composite metal layer further comprises: an electroplated metal layer, formed directly on one side of the metal bonding film opposite to the interface stabilizing layer, and located between the metal bonding film and the metal surface, wherein the connecting layer is a solder layer, and the electroplated metal layer is soldered to the metal surface through the solder layer. An electronic device as described in claim 5, wherein the electroplated metal layer is one of a copper-plated layer and a nickel-plated layer. An electronic device as described in claim 2, wherein the connecting layer is a sintered deposited layer, and the sintered deposited layer is directly between the metal bonding film and the metal surface. An electronic device as described in claim 1, wherein the power module further comprises a metal base plate, the metal base plate supports and contacts the power unit, and the metal surface is the surface of the metal base plate. An electronic device as described in claim 1, wherein the metal surface is a metal coating located on the surface of the power module. A method for manufacturing an electronic device, comprising: Providing an aluminum body of a heat sink; Providing a metal surface of a power module; Forming a composite metal layer on the aluminum body; and Fixing the composite metal layer to the metal surface through a connecting layer. The manufacturing method of the electronic device as described in claim 10, wherein the step of forming the composite metal layer on the aluminum body further includes: Partially masking the surface of the aluminum body and exposing a sputtering area from the surface; Placing the aluminum body in a vacuum chamber and performing a vacuum sputtering process on the sputtering area of the aluminum body so that an interface stabilizing layer is sputtered at a position of the surface of the aluminum body corresponding to the sputtering area, wherein the interface stabilizing layer is one of a titanium layer and a platinum layer; and The aluminum body is subjected to another vacuum sputtering process so that a metal bonding film is directly formed on the interface stabilizing layer, wherein the metal bonding film is a copper layer. The manufacturing method of the electronic device as described in claim 11, wherein the step of directly forming the metal bonding film on the interface stabilizing layer further comprises: Moving the aluminum body from the vacuum chamber into an electrolyte, and performing an electroplating process on the aluminum body so that an electroplated metal layer is directly formed on the metal bonding film, wherein the electroplated metal layer is one of a copper-plated layer and a nickel-plated layer. The manufacturing method of the electronic device as described in claim 12, wherein the step of fixing the composite metal layer to the metal surface through the connecting layer further includes: Disposing a solder between the electroplated metal layer and the metal surface to form an object to be processed; and Sending the object to be processed into a reflow soldering furnace so that the solder after being hot-melted directly forms a solder layer capable of welding the electroplated metal layer and the metal surface. The manufacturing method of the electronic device as described in claim 11, wherein the step of fixing the composite metal layer to the metal surface through the connecting layer further includes: Disposing a sintered powder between the metal bonding film and the metal surface to form an object to be processed; and Subjecting the object to be processed to a sintering process so that the sintered powder after sintering forms a sintered coating layer capable of welding the metal bonding film and the metal surface. A method for manufacturing an electronic device as described in claim 10, wherein a metal base plate of the power module carries and contacts a power unit of the power module, and the metal surface is the surface of the metal base plate. A method for manufacturing an electronic device as described in claim 10, wherein the metal surface is a metal coating located on the surface of the power module.

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